1. Field of the Invention
This invention relates to a thermal developing and transferring apparatus in which a heat-developable light-sensitive material and an image receiving material are wound around the outer peripheral surface of a heat drum and, then an image exposed on the light-sensitive material is developed and transferred to the image receiving material.
2. Description of the Related Art
A type of image recording apparatus is known in which an image is exposed on a heat-developable light-sensitive material (image forming material). These light-sensitive material and image receiving material come in contact each other, and the image of the light-sensitive material is simultaneously developed and transferred to the image receiving material.
Lengthwise sheets of thermal-developable light-sensitive material used in this type of image recording apparatus are cut in a predetermined length (e.g., 210 mm to obtain A4 sheet, or 420 mm to obtain A3 sheet), superposed one on the other and transported to a thermal development section. In the thermal developing section, the two materials are fed forward in the superposed state while being pinched between a heating drum heated at about 90.degree. C. and an endless pressing belt for a predetermined time, thereby heat-developing the light-sensitive material and transferring the image recorded on the light-sensitive material to the image receiving material.
Before the heat-developable light-sensitive material and the image receiving material are wound around the outer peripheral surface of the heating drum (between the heating drum and the endless pressing belt), these materials are superposed one on the other by a pair of pinch rollers while being kept flat, and are thereafter supplied to the periphery of the heating drum (nip between the heating drum and the endless belt). Thus, the desired reliability relating to the supply of sheets of materials to the nip between the heating drum and the endless belt is ensured.
However, it goes without saying that because one of the heat-developable light-sensitive material and the image receiving material extend inside or outside the other with respect to the radial direction of the heating drum when wound around the same. These materials are wound in the superposed state around the heating drum (between the heating drum and the endless pressing belt) with different winding radii dependent on the thicknesses of these materials. There is therefore a problem in that the materials are shifted from the normal superposed positions as they are wound around the heating drum, although they are suitably superposed by the pair of pinch rollers before they are supplied to the periphery of the heating drum. A positional transfer error is thereby caused when the image recorded on the heat-developable light sensitive material is transferred to the image receiving material, resulting in failure to obtain the desired image.